JAVASCRIPT

change one element in array javascript

var users = [
{id: 1, firstname: 'John', lastname: 'Ken'},
{id: 2, firstname: 'Robin', lastname: 'Hood'},
{id: 3, firstname: 'William', lastname: 'Cook'}
];

var editedUser = {id: 2, firstname: 'Michael', lastname: 'Angelo'};

users = users.map(u => u.id !== editedUser.id ? u : editedUser);

console.log('users -> ', users);
 Run code snippet

JavaScript Change the Elements of an Array

let dailyActivities = [ 'eat', 'sleep'];

// this will add the new element 'exercise' at the 2 index
dailyActivities[2] = 'exercise';

console.log(dailyActivities); // ['eat', 'sleep', 'exercise']